Table4.2.4.1 https://www.nco.ncep.noaa.gov/pmb/docs/grib2/grib2_doc/grib2_table4-2-4-1.shtml SPEED Velocity Magnitude (Speed) m s-1 VEL1 1st Vector Component of Velocity (Coordinate system dependent) m s-1 VEL2 2nd Vector Component of Velocity (Coordinate system dependent) m s-1 VEL3 3rd Vector Component of Velocity (Coordinate system dependent) m s-1